Research Progress of Therapeutic Vaccine for Chronic Hepatitis B

The current intended goal of antiviral therapy for chronic hepatitis B (CHB) is a "functional cure", which can be achieved in a minority of CHB patients with therapeutic agents currently available. Dysfunctional specific immune responses against hepatitis B virus (HBV) are thought to be the main cause of persistent HBV infection, and modulation of the host immune system to enhance specific cellular immune responses may contribute to HBV clearance. Therapeutic vaccines, including protein (HBsAg/preS and HBcAg), DNA and viral vector-based vaccines, are capable of inducing and enhancing HBV-specific immune responses. To date, more than 50 clinical trials have been conducted to evaluate therapeutic vaccines in the treatment of CHB, with some results showing potential for immunotherapy. This review summarizes the progress of basic and clinical research related to therapeutic vaccines for chronic HBV infection and discusses the unsatisfactory results of current clinical trials and future strategies.